Typically, an information retrieval application, e.g., a search engine, retrieves information, such as information contained in documents, in response to a query that contains one or more query, or search, terms. The search engine identifies documents, or other item containing information, scores the identified documents, and ranks the scored documents. The search engine can return the complete set of identified documents, or select some number of the top ranked documents, e.g., the documents considered to be most relevant based on their scores, in response to the query. A query contains one or more search terms, which are used as criteria for identifying the documents for retrieval. Before document scoring or ranking, a search engine typically selects documents that contain all of the query terms of a query.
Given the amount of information that is usually examined for a query, there is some degree of latency, or time delay, in responding to a query. It is desirable to minimize the query latency, or query response time, for a search engine.